I have felt a lot of conflicting things about the mood of this game, I want it dark, but the violence should be over the top. I want weird people and cultures and strange and interesting choices. I want the world to seem hopeless, but beautiful. So after more thought than I would like to admit, this is what I would like the mood of Wasteland 2 to be like.
Act 1. Around the Ranger Base
When you start the game, the people you meet and the situations you see should reinforce the inevitable decline of man. People are dirty, selfish, desperate. The help you offer is inadequate, and could never be adequate. Mankind is reverting to their basest instincts, and will surely finish the job the apocalypse started. The player's successes should feel hollow and empty, and their failure inconsequential. Hopeless.
Act 2. California
Suddenly there is an opportunity. An opportunity to really make things better. An opportunity to create, build, and connect people. The people are weird, fearful of strangers, but hoping for something better. Some will need to be destroyed, some will need to be nourished. There is much that can be salvaged, so much to learn.
The earth is lush and beautiful, plants and animals have recovered. The earth doesn't need man, but it's not trying to destroy him.
You aren't fighting to save the world, the world is already destroyed. You are searching for technologies to improve life, for people who want a better way, for a place to rebuild civilization. You are fighting to remove the ugliness, selfishness, and pettiness that are impeding a new way of life. You are fighting to defend what you create.
What you are creating doesn't have to be "good". Maybe you want to be the god, maybe you want to conquer the world. Maybe you just want to make sure everyone has enough to eat, and aren't afraid they will die in their sleep. Maybe it should be a technological utopia. But it will bring order out of chaos. How far will you go? What terrible things will you need to do?